Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

iOS Swift 2.0 Protocols Swift 2.0 Protocols Protocols With Methods

Posted by Todd Stacy
Todd Stacy
5,816 Points

the error says my code cannot be compiled, but there is no preview button to figure out why. can someone please help?

ive been working on this for more than an hour and i have no idea what could be wrong. theres no way i can debug this with out a preview button.

protocols.swift 
protocol ColorSwitchable {
    func switchColor(color: Color)
}


enum LightState {
  case On, Off
}

enum Color {
  case RGB(Double, Double, Double, Double)
  case HSB(Double, Double, Double, Double)
}

class WifiLamp: ColorSwitchable {
  let state: LightState
  var color: Color

  func switchColor(color: color)  

  init() {
    self.state = .On
    self.color = .RGB(0,0,0,0)

  }
}

1 Answer

jcorum
jcorum
71,830 Points

Yes, they say there's a Preview button, but there isn't.

class WifiLamp: ColorSwitchable {
  let state: LightState
  var color: Color

  init() {
    self.state = .On
    self.color = .RGB(0,0,0,0)
  }

  func switchColor(color: Color) {
    self.color = color
  }
}

Usually functions are written after the initializer. Not required. But a good idea. When you create a parameter for a function it needs a name, here color and a type, here Color. Note that the type must start with a capital letter. The function also needs to change the stored property color to the color passed in to the function (and stored in a local variable). Because the local variable and the stored property have the same name, color, you need to use self to disambiguate them. Think of self as meaning my. So the function is saying make my color property have the color passed in to the function.

Todd Stacy
Todd Stacy
5,816 Points

thank you so much!